Match the Following :
`{:(" Column I"," Column II"),(" (Addition of dil. HCl/dil "H_(2)SO_(4)")"," (Observation)"),("(A) "S_(2)O_(3)^(2-),"(p) Gas evolved turns lime water milky"),("(B) "SO_(3)^(2-),"(q) Gas turns lead acetate paper black"),("(C) "CO_(3)^(2-),"(r) Gas turns acidified "K_(2)Cr_(2)O_(7)" solution green"),("(D) "S^(2-),"(s) Gives white turbidity"):}`

Answer

To solve the matching question, we will analyze each ion in Column I and determine the corresponding observation in Column II when diluted HCl or H2SO4 is added.

### Step-by-Step Solution:

1. **Identify the first ion: Thiosulfite ion (S2O3^(2-))**
- When dilute HCl or H2SO4 is added to a thiosulfite compound, it results in a white turbidity in the solution.
- **Match:** (A) S2O3^(2-) → (s) Gives white turbidity.

2. **Identify the second ion: Sulfite ion (SO3^(2-))**
- Adding dilute HCl or H2SO4 to a sulfite compound releases sulfur dioxide (SO2) gas. The test for SO2 is that it turns acidified potassium dichromate (K2Cr2O7) solution from orange to green.
- **Match:** (B) SO3^(2-) → (r) Gas turns acidified K2Cr2O7 solution green.

3. **Identify the third ion: Carbonate ion (CO3^(2-))**
- When a carbonate compound reacts with dilute HCl or H2SO4, carbon dioxide (CO2) gas is produced, which turns lime water milky.
- **Match:** (C) CO3^(2-) → (p) Gas evolved turns lime water milky.

4. **Identify the fourth ion: Sulfide ion (S^(2-))**
- The reaction of a sulfide compound with dilute HCl or H2SO4 produces hydrogen sulfide (H2S) gas, which has a characteristic rotten egg smell. The test for H2S is that it turns lead acetate paper black.
- **Match:** (D) S^(2-) → (q) Gas turns lead acetate paper black.

### Final Matches:
- (A) S2O3^(2-) → (s) Gives white turbidity
- (B) SO3^(2-) → (r) Gas turns acidified K2Cr2O7 solution green
- (C) CO3^(2-) → (p) Gas evolved turns lime water milky
- (D) S^(2-) → (q) Gas turns lead acetate paper black

### Summary of Matches:
- A → s
- B → r
- C → p
- D → q